Improvement in prison-bars



einem einem JEREMIAH A. MARDEN, `or BoSroN, ASSIGNOH To CHARLES E.

' AND JOHN H. ABBOTT,` oF MALDEN, MASSACHUSETTS.

' Letters Patent No. 92,626, dated July 13, 1869.

IMPROVEMENT IN 'Parson-BARS.

The Schedule referred tp in these Letters Patent and making of the seme.

Tlnyll whom fit may concern:

Be it known that. I, JnREMLAH A. MARDEN, of Boston, in the. county`of Suffolk, and State of Massnchusetts, here invented :L new :md improved Prison- 4liar; :md l do hereby declare the hllowing to be it 4B shows an outer covering, of common cost-iron,-

chilled.

Aihe nat-ure of this invention consists in preparingr the vsunl wrought-iron prison-bin' with au outer surface or coating, that cannot be penetrated with n. saw `or other edged tool.

The chiliedfcaSt-iron surface or coating is super- .'ldded to the original wrought-iron bar by placing the original wrought-iron bm' in on iron mould, lezwing sui'licient external space for receiving the molten vmetal which forms lthe chilled surfece, in o. manner wellknown hy iron-hundcrs, and the two parts become iriniy adhered together. y

There is 11o secret in the process of thus uniting the two parts, a-ndno unusual skill is required.

The. material for the cest-iron chilled surface or coating is less expensive than the materiel used in the original wrought-iron bzn.

Thus, the expense of preparing prison-hersin this v manner is very slight.

It is evident, that when the chilled iron is'superadded to the wrought-iron bnr, the chilled coat-ing may, et choice, be of any desired thickness', and that the wrought-iron bar may be of :my desired diameter.

But I prefer that the diameter ofthe wrought-iron bin' be about three-fourths as greet ns is the entire diameter, efterthe chilled surface or conting'hos been applied, ds itis the Wrought-iron portion that is re lied on for strength.

Having thus described my invention, l, VVhet I claim, mid desire to secure by Letters Patent is- A, l

'l7he iron prison-bnr, constructed as described, and for the purpose set forth.

JEREMIAH A. MARDEN.

.Witnesses S. E. D. CURRIER, Geo. MomnLL. 

